U.S. patent application number 11/482397 was filed with the patent office on 2007-02-22 for tantalum and niobium compounds and their use for chemical vapour deposition (cvd).
This patent application is currently assigned to H.C. STARCK. Invention is credited to Alexei Merkoulov, Thomas Ochs, Michael Pokoj, Knud Reuter, Wolfgang Stolz, Jorg Sundermeyer, Kerstin Volz.
Application Number | 20070042213 11/482397 |
Document ID | / |
Family ID | 37529343 |
Filed Date | 2007-02-22 |
United States Patent
Application |
20070042213 |
Kind Code |
A1 |
Reuter; Knud ; et
al. |
February 22, 2007 |
Tantalum and niobium compounds and their use for chemical vapour
deposition (CVD)
Abstract
Tantalum and niobium compounds having the general formula (I)
and their use for the chemical vapour deposition process are
described: ##STR1## wherein M stands for Nb or Ta, R.sup.1 and
R.sup.2 mutually independently denote optionally substituted
C.sub.1 to C.sub.12 alkyl, C.sub.5 to C.sub.12 cycloalkyl, C.sub.6
to C.sub.10 aryl radicals, 1-alkenyl, 2-alkenyl, 3-alkenyl,
triorganosilyl radicals --SiR.sub.3, or amino radicals NR.sub.2
where R.dbd.C.sub.1 to C.sub.4 alkyl, R.sup.3 denotes an optionally
substituted C.sub.1 to C.sub.8 alkyl, C.sub.5 to C.sub.10
cycloalkyl, C.sub.6 to C.sub.14 aryl radical, or SiR.sub.3 or
NR.sub.2, R.sup.4 denotes halogen from the group comprising Cl, Br,
I, or NH--R.sup.5 where R.sup.5.dbd.optionally substituted C.sub.1
to C.sub.8 alkyl, C.sub.5 to C.sub.10 cycloalkyl or C.sub.6 to
C.sub.10 aryl radical, or O--R.sup.6 where R.sup.6=optionally
substituted C.sub.1 to C.sub.11 alkyl, C.sub.5 to C.sub.10
cycloalkyl, C.sub.6 to C.sub.10 aryl radical, or --SiR.sub.3, or
BH.sub.4, or an optionally substituted allyl radical, or an indenyl
radical, or an optionally substituted benzyl radical, or an
optionally substituted cyclopentadienyl radical, or --NR--NR'R''
(hydrazido(-1), wherein R, R' and R'' have the aforementioned
meaning of R, or CH.sub.2SiMe.sub.3, pseudohalide (e.g. --N.sub.3),
or silylamide --N(SiMe.sub.3).sub.2, R.sup.7 and R.sup.8 mutually
independently denote H, optionally substituted C.sub.1 to C.sub.12
alkyl, C.sub.5 to C.sub.12 cycloalkyl or C.sub.6 to C.sub.10 aryl
radicals.
Inventors: |
Reuter; Knud; (Krefeld,
DE) ; Sundermeyer; Jorg; (Marburg, DE) ;
Merkoulov; Alexei; (Freiburg, DE) ; Stolz;
Wolfgang; (Marburg, DE) ; Volz; Kerstin;
(Dautphetal, DE) ; Pokoj; Michael; (Fernwald,
DE) ; Ochs; Thomas; (Kirchheim-Betziesdorf,
DE) |
Correspondence
Address: |
CONNOLLY BOVE LODGE & HUTZ, LLP
P O BOX 2207
WILMINGTON
DE
19899
US
|
Assignee: |
H.C. STARCK
Goslar
DE
|
Family ID: |
37529343 |
Appl. No.: |
11/482397 |
Filed: |
July 7, 2006 |
Current U.S.
Class: |
428/620 ;
106/287.18; 106/287.3; 556/33; 556/42 |
Current CPC
Class: |
C23C 16/34 20130101;
C07F 9/005 20130101; Y10T 428/12528 20150115 |
Class at
Publication: |
428/620 ;
106/287.18; 106/287.3; 556/033; 556/042 |
International
Class: |
C07F 9/00 20060101
C07F009/00; H01L 21/316 20060101 H01L021/316 |
Foreign Application Data
Date |
Code |
Application Number |
Jul 15, 2005 |
DE |
102005033102.5 |
Claims
1. Compounds having the general formula (I) ##STR22## wherein M
stands for Ta or Nb, R.sup.1 and R.sup.2 mutually independently
denote optionally substituted C.sub.1 to C.sub.12 alkyl, C.sub.5 to
C.sub.12 cycloalkyl or C.sub.6 to C.sub.10 aryl radicals,
1-alkenyl, 2-alkenyl, 3-alkenyl or triorganosilyl radicals --SiR3,
or amino radicals NR.sub.2 wherein R stands for a C.sub.1 to
C.sub.4 alkyl radical, R.sup.3 denotes an optionally substituted
C.sub.1 to C.sub.8 alkyl, C.sub.5 to C.sub.10 cycloalkyl, C.sub.6
to C.sub.14 aryl radical, or SiR.sub.3, or NR.sub.2 wherein R has
the aforementioned meaning, R.sup.4 denotes halogen from the group
comprising Cl, Br, I, or NH--R.sup.5 where R.sup.5=optionally
substituted C.sub.1 to C.sub.8 alkyl, C.sub.5 to C.sub.10
cycloalkyl or C.sub.6 to C.sub.10 aryl radical, or O--R.sup.6 where
R.sup.6= optionally substituted C.sub.1 to C.sub.11 alkyl, C.sub.5
to C.sub.10 cycloalkyl or C.sub.6 to C.sub.10 aryl radical, or
--SiR.sub.3, or BH.sub.4, or an optionally substituted allyl
radical, or an indenyl radical, or an optionally substituted benzyl
radical, or an optionally substituted cyclopentadienyl radical, or
--NR--NR'R'' (hydrazido(-1), wherein R, R' and R'' mutually
independently have the aforementioned meaning of R, or
CH.sub.2SiMe.sub.3, pseudohalide (e.g. --N.sub.3), or silylamide
--N(SiMe.sub.3).sub.2, R.sup.7 and R.sub.8 mutually independently
denote H, optionally substituted C.sub.1 to C.sub.12 alkyl, C.sub.5
to C.sub.12 cycloalkyl or C.sub.6 to C.sub.10 aryl radicals.
2. Compounds according to claim 1 corresponding to the general
formula II, ##STR23## wherein M stands for Ta or Nb, R.sup.1 and
R.sup.2 denote identical C.sub.1 to C.sub.5 alkyl or C.sub.5 to
C.sub.6 cycloalkyl radicals, R.sup.3 denotes a C.sub.1 to C.sub.5
alkyl, C.sub.5 to C.sub.6 cycloalkyl or optionally substituted
phenyl radical, R.sup.4 denotes a halogen from the group comprising
Cl, Br, I, a radical NH--R.sup.5 where R.sup.5.dbd.C.sub.1 to
C.sub.5 alkyl, C.sub.5 to C.sub.6 cycloalkyl or optionally
substituted C.sub.6 to C.sub.10 aryl radical, or BH.sub.4, or an
optionally substituted allyl radical, or an optionally substituted
benzyl radical, or an optionally substituted cyclopentadienyl
radical or an oxyalkyl radical.
3. Compounds according to claim 1 corresponding to the general
formula (Il), ##STR24## wherein R.sup.3 and R.sup.4 mutually
independently denote an identical or different radical from the
group of C.sub.1 to C.sub.5 alkyl radicals, or C.sub.6 to C.sub.10
aryl radicals optionally substituted by one to three C.sub.1 to
C.sub.5 alkyl groups.
4. Compounds according to claim 2 selected from the group
consisting of: ##STR25##
5. Compounds according to claim 2 corresponding to the general
formula (XI), ##STR26## wherein R.sup.6 denotes an optionally
substituted C.sub.1 to C.sub.12 alkyl radical.
6. Compound according to claim 5 corresponding to the structure
(XII): ##STR27##
7. Compounds according to claim 2 corresponding to the general
structure (XIII), ##STR28## wherein R.sup.9 denotes a radical of an
enolate having the formula (XIV), ##STR29## in which R.sup.10
denotes a C.sub.1 to C.sub.4 alkyl radical and R.sup.11 is the same
as R.sup.10 or mutually independently denotes OR.sup.10.
8. Tantalum-containing coatings comprising a compound of claim 1,
deposited by means of the chemical vapour deposition process.
9. Substrates comprising a tantalum-containing coating, produced
from a compound according to claim 1 .
10. Niobium-containing coatings comprising a compound of claim 1,
deposited by means of the chemical vapour deposition process.
11. Substrates comprising a niobium-containing coating produced
from a compound according to claim 1 .
12. TaN-containing coatings comprising a compound of claim 1,
deposited by means of the chemical vapour deposition process.
13. NbN-containing coatings comprising a compound of claim 1,
deposited by means of the chemical vapour deposition process.
Description
CROSS-REFERENCE TO RELATED APPLICATION
[0001] This application claims priority under 35 U.S.C.
.sctn.119(a-e) to German application DE 10 2005 033102, filed Jul.
15, 2005.
FIELD OF THE INVENTION
[0002] The present invention concerns special novel tantalum and
niobium compounds, their use for the deposition of tantalum- or
niobium-containing coatings by chemical vapour deposition and the
tantalum- or niobium-containing coatings produced by this
process.
BACKGROUND OF THE INVENTION
[0003] Ta-- and Ta--N-based mixed system coatings for use in Si
microelectronics are currently produced by means of plasma-based
deposition methods (physical vapour deposition (PVD)). In view of
the extreme requirements for ever more highly integrated switching
circuits, e.g. uniform coating deposition on textured surfaces, PVD
processes are increasingly being pushed to the limits of what is
technically feasible. For these applications, chemical gas phase
deposition methods (chemical vapour deposition (CVD)) through to
film deposition with atomic layer precision using a special CVD
method known as atomic layer deposition (ALD) are increasingly
coming into use. For these CVD processes the appropriate chemical
starting materials for the individual elements must naturally be
available for the coatings that are required in each case.
[0004] At present, halides such as e.g. TaCl.sub.5, TaBr.sub.5, see
WO 2000065123 A1, A. E. Kaloyeros et al., J. Electrochem. Soc. 146
(1999), p. 170-176, or K. Hieber, Thin Solid Films 24 (1974), p.
157-164), are mainly used for the CVD of Ta-based coating
structures. There are a number of disadvantages associated with
this practice. Firstly, halogen radicals are undesirable in many
ways for the formation of complex coating structures because of
their caustic/corrosive properties, and secondly tantalum halides
exhibit disadvantages due to their low volatility and difficult
processing characteristics as high-melting solids. Simple
tantalum(V) amides, such as e.g. ((CH.sub.3).sub.2N).sub.5Ta, are
likewise proposed, see e.g. Fix et al., Chem. Mater., 5 (1993), p.
614-619. However, with the simple amides only certain decomposition
ratios of Ta to N can usually be established, which make the
accurate control of the individual concentrations of elements in
the coatings more difficult. In many cases Ta(V) nitride films are
formed (see e.g. Fix et al.: Ta.sub.3N.sub.5) rather than the
desired electrically conductive Ta(III) nitride coatings (TaN).
Furthermore, the films produced with these starting materials very
often exhibit high, undesirable concentrations of carbon. For that
reason Tsai et al., Appl. Phys. Lett. 67(8), (1995), p. 1128-1130,
proposed t-BuN.dbd.Ta(NEt.sub.2).sub.3 in TaN CVD at 600.degree. C.
Because of its relatively low volatility, this compound requires a
high plant temperature and is therefore not very compatible with
the typical production processes for integrated switching circuits.
Other, similar tantalum amide imides have also been proposed, see
e.g. Chiu et al., J. Mat. Sci. Lett. 11 (1992), p. 96-98, with
which, however, without additional reactive gas, high carbon
contents were obtained in the tantalum nitride coatings. More
recently, other tantalum nitride precursors have been proposed,
e.g. by Bleau et al., Polyhedron 24(3), (2005), p. 463-468, which
because of their complexity and laborious production exhibit
disadvantages from the outset, or special cyclopentadienyl
compounds, which either inevitably lead to TaSiN (not tantalum
nitride) or require an additional, not otherwise specified nitrogen
source (Kamepalli et al., US Pat. Appl. Publ. 2004142555 A1,
Priority Jan. 16, 2003, ATMI, Inc.). In U.S. Pat. No. 6,593,484
(Kojundo Chemicals Laboratory Co., Ltd., Japan) a suitable special
tantalum amide imide is proposed, although the specified synthesis
can only be reproduced poorly and with difficulty.
[0005] A considerable need can thus be identified for other, novel
precursors for TaN coatings which do not have the aforementioned
disadvantages or which at least bring about clear improvements.
SUMMARY OF THE INVENTION
[0006] The object underlying the present invention was therefore to
provide such precursors.
[0007] The invention concerns complex tantalum amides having a DAD
ligand which meets these requirements. DAD stands for radicals
having the general structure (A) derived from 1,4-diazabutadiene
##STR2## wherein
[0008] R.sup.1 and R.sup.2 mutually independently denote optionally
substituted C.sub.1 to C.sub.12 alkyl, C.sub.5 to C.sub.12
cycloalkyl, C.sub.6 to C.sub.10 aryl radicals, 1-alkenyl,
2-alkenyl, 3-alkenyl, triorganosilyl radicals --SiR.sub.3 or amino
radicals NR.sub.2, wherein R stands for a C.sub.1 to C.sub.4 alkyl
radical, R.sup.7 and R.sup.8 mutually independently denote H,
optionally substituted C.sub.1 to C.sub.12 alkyl, C.sub.5 to
C.sub.12 cycloalkyl or C.sub.6 to C.sub.10 aryl radicals.
[0009] The invention also concerns the analogous niobium compounds
which are suitable for example as CVD precursors for conductive
niobium-nitride coatings (NbN).
[0010] The invention provides compounds having the general formula
(1), ##STR3## wherein
[0011] M stands for Nb or Ta,
[0012] R.sup.1 and R.sup.2 mutually independently denote optionally
substituted C.sub.1 to C.sub.12 alkyl, C.sub.5 to C.sub.12
cycloalkyl, C.sub.6 to C.sub.10 aryl radicals, 1-alkenyl,
2-alkenyl, 3-alkenyl, triorganosilyl radicals --SiR.sub.3 or amino
radicals NR.sub.2 wherein R stands for a C.sub.1 to C.sub.4 alkyl
radical,
[0013] R.sup.3 denotes an optionally substituted C.sub.1 to C.sub.8
alkyl, C.sub.5 to C.sub.10 cycloalkyl, C.sub.6 to C.sub.14 aryl
radical, SiR.sub.3 or NR.sub.2, wherein R has the aforementioned
meaning,
[0014] R.sup.4 denotes halogen from the group comprising Cl, Br, I,
or NH--R.sup.5 where R.sup.5=optionally substituted C.sub.1 to
C.sub.8 alkyl, C.sub.5 to C.sub.10 cycloalkyl or C.sub.6 to
C.sub.10 aryl radical, or O--R.sup.6 where R.sup.6=optionally
substituted C.sub.1 to C.sub.11 alkyl, C.sub.5 to C.sub.10
cycloalkyl, C.sub.6 to C.sub.10 aryl radical, or --SiR.sub.3, or
BH.sub.4, or an optionally substituted allyl radical, or an indenyl
radical, or an optionally substituted benzyl radical, or an
optionally substituted cyclopentadienyl radical, or --NR--NR'R''
(hydrazido(-1), wherein R, R' and R'' mutually independently have
the cited meaning of R or CH.sub.2SiMe.sub.3, pseudohalide (e.g.
--N.sub.3), or silylamide --N(SiMe.sub.3).sub.2, R.sup.7 and
R.sup.8 mutually independently denote H, optionally substituted
C.sub.1 to C.sub.12 alkyl, C.sub.5 to C.sub.12 cycloalkyl or
C.sub.6 to C.sub.10 aryl radicals.
[0015] Unless otherwise specified, substituted in this context is
understood to refer to a substitution with C.sub.1 to C.sub.4
alkoxy or di-(C.sub.1 to C.sub.4 alkyl) amino radicals.
DETAILED DESCRIPTION OF THE INVENTION
[0016] As used herein in the specification and claims, including as
used in the examples and unless otherwise expressly specified, all
numbers may be read as if prefaced by the word "about", even if the
term does not expressly appear. Also, any numerical range recited
herein is intended to include all sub-ranges subsumed therein.
[0017] The tantalum and niobium compounds according to the
invention can be used to produce tantalum- and/or
niobium-containing metals, metal alloys, oxides, nitrides and
carbides and mixtures thereof, and/or compounds in amorphous and/or
crystalline form, by means of CVD, ALD (atomic layer deposition)
and thermal decomposition. Such mixtures and compounds are used
e.g. as dielectric coatings in capacitors and gates in transistors,
microwave ceramics, piezo-ceramics, thermal and chemical barrier
coatings, diffusion barrier coatings, hard material coatings,
electrically conductive coatings, antireflective coatings, optical
coatings and coatings for IR mirrors. One example of optical
materials are Li tantalates and niobates. Examples of electrically
conductive and corrosion-resistant coatings for electrodes are
tantalum- and/or niobium-containing titanium and ruthenium mixed
oxides. Tantalum and niobium compounds according to the invention
are also suitable as precursors for flame pyrolysis for the
production of powders.
[0018] Tantalum and niobium imides having the general formula (II)
are preferred, ##STR4## wherein
[0019] M stands for Ta or Nb,
[0020] R.sup.1 and R.sup.2 denote identical C.sub.1 to C.sub.5
alkyl or C.sub.5 to C.sub.6 cycloalkyl radicals,
[0021] R.sup.3 denotes a C.sub.1 to C.sub.5 alkyl, C.sub.5 to
C.sub.6 cycloalkyl or optionally substituted phenyl radical, or
SiR.sub.3, or NR.sub.2, wherein R stands for C.sub.1 to C.sub.4
alkyl,
[0022] R.sup.4 denotes a halogen from the group comprising Cl, Br,
I, a radical NH--R.sup.5 where R.sup.5.dbd.C.sub.1 to C.sub.5
alkyl, C.sub.5 to C.sub.6 cycloalkyl or optionally substituted
C.sub.6 to C.sub.10 aryl radical, or BH.sub.4, or an optionally
substituted allyl radical, or an indenyl radical, or an optionally
substituted benzyl radical, or an optionally substituted
cyclopentadienyl radical or an oxyalkyl radical.
[0023] Tantalum amide imides having tert-butyl-substituted DAD
ligands displaying the structure (1) are particularly preferred:
##STR5## wherein
[0024] R.sup.3 and R.sup.4 mutually independently denote an
identical or different radical from the group of C.sub.1 to C.sub.5
alkyl radicals, or C.sub.6 to C.sub.10 aryl radicals optionally
substituted by one to three C.sub.1 to C.sub.5 alkyl groups, or
SiR.sub.3 or NR.sub.2.
[0025] The compound having the structure (IV) ##STR6## is most
particularly preferred.
[0026] The analogous compounds having formula (V) ##STR7## and the
analogous compound having the structure (VI), which in particular
is usually in dimeric form, ##STR8## are likewise most particularly
preferred.
[0027] Other most particularly preferred compounds are those having
the structure (III), ##STR9## the structure (VII), ##STR10## the
structure (IX), ##STR11## and the structure (X). ##STR12##
[0028] Particularly preferred compounds are moreover those having
the general formula (XI), ##STR13## wherein
[0029] R.sup.6 denotes an optionally substituted C.sub.1 to
C.sub.12 alkyl radical.
[0030] From this group the compound having the structure (XII) is
particularly preferred. ##STR14##
[0031] Other preferred compounds are those having the general
structure (XI), ##STR15## wherein
[0032] R.sup.9 denotes a radical of an enolate having the formula
(XIV), ##STR16## in which
[0033] R.sup.10 denotes a C.sub.1 to C.sub.4 alkyl radical and
R.sup.11 is the same as R.sup.10 or mutually independently denotes
OR.sup.10.
[0034] Alkyl or alkoxy stands independently in each case for a
straight-chain, cyclic or branched alkyl or alkoxy radical, wherein
the cited radicals can optionally be further substituted. The same
applies for the alkyl portion of a trialkylsilyl or mono- or
dialkyl amino radical or the alkyl portion of mono- or dialkyl
hydrazines or mono-, di-, tri- or tetraalkyl silanes.
[0035] Within the context of the invention, C.sub.1-C.sub.4 alkyl
stands, for example, for methyl, ethyl, n-propyl, isopropyl,
n-butyl, sec-butyl, tert-butyl, C.sub.1-C.sub.5 alkyl stands in
addition for example for n-pentyl, 1-methylbutyl, 2-methylbutyl,
3-methylbutyl, neopentyl(2,2-dimethylpropyl), 1-ethylpropyl,
1,1-dimethylpropyl, 1,2-dimethylpropyl, C.sub.1-C.sub.6 alkyl
stands in addition for example for n-hexyl, 1-methylpentyl,
2-methylpentyl, 3-methylpentyl, 4-methylpentyl, 1,1-dimethylbutyl,
1,2-dimethylbutyl, 1,3-dimethylbutyl, 2,2-dimethylbutyl,
2,3-dimethylbutyl, 3,3-dimethylbutyl, 1-ethylbutyl, 2-ethylbutyl,
1,1,2-trimethylpropyl, 1,2,2-trimethylpropyl,
1-ethyl-l-methylpropyl or 1-ethyl-2-methylpropyl, C.sub.1-C.sub.12
alkyl stands in addition for example for n-heptyl and n-octyl,
n-nonyl, n-decyl and n-dodecyl.
[0036] 1-Alkenyl, 2-alkenyl, 3-alkenyl stand for example for the
alkenyl groups corresponding to the above alkyl groups.
C.sub.1-C.sub.4 alkoxy stands for example for the alkoxy groups
corresponding to the above alkyl groups, such as e.g. methoxy,
ethoxy, n-propoxy, isopropoxy, n-butoxy, sec-butoxy,
tert-butoxy.
[0037] C.sub.5-C.sub.12 cycloalkyl stands for example for
optionally substituted mono-, bi- or tricyclic aLkyl radicals.
Examples are cyclopentyl, cyclohexyl, cycloheptyl, pinanyl,
adamantyl, the isomeric menthyls, n-nonyl, n-decyl, n-dodecyl.
Cyclopentyl and cyclohexyl are preferred. as C.sub.5-C.sub.6
cycloalkyl.
[0038] Aryl stands independently in each case for an aromatic
radical having 6 to 14, preferably 6 to 10 skeletal carbon atoms,
in which none, one, two or three skeletal carbon atoms per cyclic
compound can be replaced by heteroatoms selected from the group
comprising nitrogen, sulfur or oxygen, preferably however for a
carbocyclic aromatic radical having 6 to 14, preferably 6 to 10
skeletal carbon atoms.
[0039] Examples of optionally substituted C.sub.6-C.sub.10 aryl are
phenyl, 2,6-diisopropyl phenyl, o-, p-, m-tolyl or naphthyl.
[0040] The carbocyclic aromatic radical or heteroatomic radical can
also be substituted with up to five identical or different
substituents per cyclic compound, which are selected from the group
comprising fluorine, cyano, C.sub.1-C.sub.12 alkyl,
C.sub.1-C.sub.12 fluoroalkyl, C.sub.1-C.sub.2 fluoroalkoxy,
C.sub.1-C.sub.12 alkoxy or di(C.sub.1-C.sub.8 alkyl) amino.
[0041] The compounds according to the invention can be produced in
a simple manner by reacting DAD ligand precursors having the
general formula (B) ##STR17## wherein R.sup.1, R.sup.2, R.sup.5 and
R.sup.6 have the aforementioned meaning,
[0042] in the presence of at least one reducing agent with Ta or Nb
complexes having the general formula (C),
[M(NR.sup.3)(R.sup.4)Cl.sub.2L.sub.2]
[0043] wherein
[0044] M stands for Ta or Nb
[0045] L stands for a ligand selected from aliphatic or aromatic
amines, ethers, halide, preferably chloride, or nitriles,
preferably acetonitrile,
[0046] R.sup.3 or R.sup.4 have the aforementioned meaning,
[0047] in a suitable solvent, preferably at a temperature of
-20.degree. C. to 120.degree. C.
[0048] Possible examples of suitable reducing agents are non-noble
metals such as e.g. Mg, Zn, Li, Na, Al, etc. Suitable solvents are
for example ethers, such as e.g. THF, diethyl ether or
1,2-dimethoxyethane, dipolar-aprotic solvents, such as e.g.
acetonitrile, N,N-dimethyl formamide or tert-amines or aliphatic or
aromatic hydrocarbons, such as e.g. toluene, pentane, hexane, etc.,
and mixtures of these or mixtures with optionally other solvents.
The Ta or Nb complexes having the general formula (C)
[M(NR.sup.3)(R.sup.4)Cl.sub.2L.sub.2] can be produced by generally
known processes in isolated form or in situ.
[0049] Moreover, it is also possible to reduce the DAD ligand
precursor having the general formula (B) in advance in a suitable
solvent with the reducing agent, such that solutions of the
pre-reduced DAD ligands, such as, with Li as reducing agent for
example, Li[DAD] or Li.sub.2[DAD], are reacted with the solution of
the complexes having the general formula (C). With a careful choice
and control of the reaction temperature between -20.degree. C. and
120.degree. C. it is also possible to produce the compounds
according to the invention in a one-pot synthesis, in which e.g.
TaCl.sub.5 is combined and reacted with the amine(s)
H.sub.2NR.sup.3 or H.sub.2NR.sup.4, the reducing agent and the DAD
ligand precursor having the general formula (B).
[0050] In order to isolate the compounds according to the
invention, the solvent is removed by distillation, for example,
under reduced pressure, and this can be followed by a further
purification by washing and a subsequent drying. Such suitable
processes are known to the person skilled in the art.
[0051] The invention also provides the use of compounds according
to formula I as a precursor for tantalum nitride (TaN) coatings by
means of chemical vapour deposition and the TaN coatings produced
accordingly by CVD from the compounds having formula L. Compounds
having formula II are preferably used in these processes,
particularly preferably compounds having formula III, most
particularly preferably compounds having formula IV to XII. The
definition of the radicals here corresponds to the definitions
given above.
[0052] The invention also provides substrates exhibiting a TaN or
an NbN coating which is produced from compounds having formula I or
preferably formula II with the aforementioned definitions for the
various radicals.
[0053] The following points are to be regarded as technical
advantages of the compounds proposed in the present invention:
[0054] 1) The synthesis of the volatile Ta and Nb compounds does
not require expensive lithium alkyls or amides.
[0055] 2) The introduction of the DAD ligand as a CVD-compatible
starting group for Ta(III) or Nb(III) coatings reduces the risk of
an undesirable incorporation of C in the substrate coating.
[0056] 3) Through the introduction of additional stable starting
groups, such as e.g. cyclopentadienyl (Cp) or boronate (BH.sub.4),
the reduction of C incorporation in CVD is further encouraged.
[0057] 4) In the combination with N starting materials, for example
hydrazine derivatives (such as e.g. 1,1-dimethylhydrazine or
tert-butylhydrazine), a selective modification of the coating
composition is possible during CVD.
[0058] 5) Selective influencing of the oxidation state of Ta(B) or
Ta(V) compounds and their Nb analogues.
[0059] The invention also concerns the use of the Ta and Nb
compounds according to the invention for the deposition of Ta-- or
Nb-containing coatings, optionally with incorporation of other
compounds, for the defined establishment of certain concentrations
of the various elements in the coating by means of chemical vapour
deposition (CVD) with the following process steps: A suitable
substrate, such as e.g. a Si wafer or a Si wafer already exhibiting
other surface-textured single or multiple coatings, as are
typically used for the manufacture of Si-based integrated switching
circuits, is introduced into a CVD plant and heated to a
temperature suitable for coating deposition in the range from
250.degree. C. to 700.degree. C. A carrier gas is loaded with the
starting materials in defined concentrations, wherein inert gases
such as e.g. N.sub.2 and/or Ar, also in combination with inert,
evaporated solvents such as e.g. hexane, heptane, octane, toluene
or butyl acetate, can be used as the carrier gas, and reactive,
e.g. reducing gases such as e.g. H.sub.2 can also be added. The
loaded carrier gas is passed for a defined exposure time over the
surface of the heated substrate, the concentrations being adapted
to the starting materials and the exposure time, with the proviso
that a Ta-- or Nb-containing coating is formed with a predefined
coating thickness and a predefined composition on the surface of
the substrate in amorphous, nanocrystalline, microcrystalline or
polycrystalline form. Depending on the deposition rate, typical
exposure times are, for example, a few seconds to several minutes
or hours. Typical deposition rates can be from 0.1 nm/sec to 1
nm/sec, for example. Other deposition rates are also possible,
however. Typical coating thicknesses are e.g. 0.1 to 100 nm,
preferably 0.5 to 50 nm, particularly preferably 1 to 10 nm.
[0060] Within the context of CVD technology, in addition to the
starting materials according to formula I, preferably formulae II
to XIII, for the production of pure Ta or Nb metal coatings (Ta--
or Nb-rich single coatings), Ta-- or Nb-rich coatings and TaN-- or
NbN-containing mixed coatings, the following starting materials can
also be used for selective establishment of the N concentration in
TaN-- or NbN-containing mixed system coatings--also referred to
below as N starting materials: ammonia (NH.sub.3) or
C.sub.1-C.sub.8 monoalkylhydrazines, in particular
tert-butylhydrazine (.sup.tBu-NH--NH.sub.2), and/or
C.sub.1-C.sub.5-1,1-dialkylhydrazines, in particular
1,1-dimethyl-hydrazine ((CH.sub.3).sub.2N--NH.sub.2), wherein the
alkyl groups can be linear or branched. To influence the stability
of the mixed system coatings that are produced in the subsequent
high-temperature full cure steps in particular, the incorporation
of other elements in the CVD deposition can be beneficial in order
to influence the recrystallisation characteristics of the coating
that is formed. The element Si is particularly suitable for use in
Si-based integrated switching circuits. In addition to the
aforementioned starting materials, the following starting materials
for Si-- also referred to below as Si starting materials--are
advantageously used in CVD technology for the production of mixed
system coatings containing Ta(or Nb)--N--Si: silane (SiH.sub.4)
and/or disilane (Si.sub.2H.sub.6) and/or C.sub.1-C.sub.8 monoalkyl
silanes, in particular tert-butyl silane (tBu-SiH.sub.3), and/or
C.sub.1-C.sub.8 dialkyl silanes, in particular di-tert-butyl silane
(tBu.sub.2SiH.sub.2), and/or C.sub.1-C.sub.8 trialkyl silanes, in
particular triethyl silane ((C.sub.2H.sub.5).sub.3SiH), and/or
C.sub.1-C.sub.8 tetraalkyl silanes, in particular tetraethyl silane
((C.sub.2H.sub.5).sub.4Si), wherein the alkyl groups can be linear
or branched.
[0061] The exact concentrations of the starting materials are
determined in principle by the thermal decomposition
characteristics of the individual starting materials in the CVD
process. The starting materials are preferably used in the
following molar ratios: N starting material/Ta or Nb starting
material 0 to 20,000, Si starting materials/Ta or Nb starting
material 0-100. The surface temperature of the substrate is
preferably set in the range from 300.degree. C. to 600.degree. C.
The overall pressure of carrier gas and starting materials is
preferably established at pressures in the range from 10 hPa to
1000 hPa, the ratio of the partial pressure of the sum of all
starting materials to the partial pressure of the carrier gas being
between 0.0001 and 0.5. The deposition rate is preferably 0.05
nm/min to 50 nm/min.
[0062] The tantalum and niobium compounds according to the
invention are also suitable as precursors for tantalum oxide
(Ta.sub.2O.sub.5) coatings and niobium oxide (Nb2O5) coatings,
which are of interest for microelectronics because of their high
dielectric constants.
[0063] The examples below serve to illustrate the invention by way
of example and should not be regarded as a limitation.
EXAMPLES
[0064] In the examples below the abbreviations and abbreviated
compound names denote the following structures:
[0065] D.sup.tBuAD=1,4-di-tert-butyl-1,4-diazabutadiene ##STR18##
or its divalent radical
[0066] .sup.tBu=tert-butyl
[0067] .sup.tBuN=tert-butyl imino .sup.tBu-N.dbd.
[0068] Me=methyl
[0069] Py=pyridine
[0070] Bz=benzyl
[0071] AcAc=monovalent radical of the enolate form of acetyl
acetone= ##STR19##
[0072] Cp=cyclopentadienyl
[0073] Ind=monovalent radical of indene ##STR20##
[0074] Dip=2,6-di-isopropyl phenyl ##STR21##
[0075] all=allyl
EXAMPLES FOR THE PRODUCTION OF INTERMEDIATES NOT ACCORDING TO THE
INVENTION INTERMEDIATE EXAMPLE A
Production of Li.sub.2D.sup.tBuAD
[0076] 870 mg (125 mmol) of lithium were added to a solution of 10
g (60 mmol) of D.sup.tBuAD in 200 ml of diethyl ether with cooling.
After stirring for 8 h at 23.degree. C., the orange-coloured
solution was filtered. The solvent was then distilled off at 20
mbar and the residue dried in high vacuum for 48 h. Yield 10.8 g
(almost quantitative).
[0077] Analysis:
[0078] .sup.1H--NMR (.delta. against TMS, C.sub.6D.sub.5CD.sub.3,
300 K, 200 MHz): 5.52 (s, 2H), 1.10 (s; 18H).
INTERMEDIATE EXAMPLE B
Production of [Ta(.sup.tBuN)(.sup.tBuNH)Cl.sub.2.2Py]
[0079] 61.3 ml of .sup.tBuNH.sub.2 (587 mmol) in 50 ml of
CH.sub.2Cl.sub.2 were added dropwise to a suspension of 21.0 g of
TaCl.sub.5 (58.7 mmol) in 200 ml of CH.sub.2Cl.sub.2 with cooling.
The reaction mixture was then heated to 23.degree. C. and stirred
for 4 h. The suspension obtained was cooled again with an ice bath
and a solution of 23.7 ml (294 mmol) of pyridine in 50 ml of
CH.sub.2Cl.sub.2 was added. After stirring for 4 h at 23.degree.
C., 150 m of hexane were added to the reaction mixture and the
solution obtained was filtered through celite. The residue was
washed twice more with 100 ml of CH.sub.2Cl.sub.2/hexane 1:1 until
it was colourless. The combined solutions were freed from all
volatile components at 20 mbar, the residue was washed with hexane
and dried. Pale yellow, microcrystalline product, yield 25.9 g (84%
of theoretical), melting point >120.degree. C.
(decomposition).
[0080] Elemental Analysis Calculated (%) for
C.sub.18H.sub.29N.sub.4Cl.sub.2Ta (M=553.31 gmol.sup.-1): C, 39.07;
H, 5.29; N, 10.13. Found (%): C, 40.15; H, 5.17; N, 10.02.
[0081] MS-EI: 379 (M.sup.+-2Py-Me, 20%), 323
(M.sup.+-2Py-(CH.sub.3).sub.2CCH.sub.2-Me, 42%), 41 (100%).
[0082] .sup.1H-NMR (300.1 MHz, CDCl.sub.3): .delta.=1.28 (s, 9H,
NHC(CH.sub.3).sub.3), 1.31 (s, 9H, NC(CH.sub.3).sub.3), 7.44
(pseudo-t, 4H, m-H.sub.py), 7.86 (tt, J.sub.1=7.7 Hz, J.sub.2=1.5
Hz, 2H, p-Hpy), 8.60 (broad s, 1H, NHC(CH.sub.3).sub.3), 9.40 (dd,
J.sub.1=6.9 Hz, J.sub.2=1.5 Hz, 4H, o-H.sub.py)
[0083] .sup.13C{.sup.1H}-NMR (CDCl.sub.3, 75 MHz, 300 K): 32.3
(NC(CH.sub.3).sub.3), 33.9 (NHC(CH.sub.3).sub.3), 56.4
(NHC(CH.sub.3).sub.3), 64.8 (s, NC(CH.sub.3).sub.3), 124.1 (m-Py),
139.2 (p-Py), 153.5 (o-Py).
INTERMEDIATE EXAMPLE C
Production of [(D.sup.tBuAD)(.sup.tBuN)Ta(.mu.-Cl)].sub.2
[0084] 43.8 ml of tert-butylamine (418.7 mmol) were added dropwise
at 0.degree. C. with stirring to a suspension of 50.00 g of
TaCl.sub.5 (139.6 mmol) in 300 ml of CH.sub.2Cl.sub.2. The reaction
mixture was heated to 23.degree. C. and stirred for 3 h at this
temperature. 23.49 g (139.6 mmol) of DtBuAD were then added and the
resulting suspension was stirred for 8 h. The mixture was then
filtered following the addition of 150 ml of hexane. The volatile
components were removed from the filtrate at 20 mbar and the
residue then dissolved in 200 ml of THF. 1.94 g (279.2 mmol) of
lithium powder were then added slowly with cooling (immediate dark
brown coloration). After stirring for 8 h the solvent was
evaporated off at 20 mbar and the residue extracted twice with 150
ml of diethyl ether each time. The solvent was evaporated off from
the extract at 20 mbar. The residue was sublimated at 160.degree.
C./10.sup.-4 mbar. Yield: 38.8 g (61% of theoretical), melting
point 150.0.degree. C.
[0085] Elemental analysis: Calculated (%) for monomeric
C.sub.14H.sub.29N.sub.3ClTa (M=455.81 g mol.sup.-1): C, 36.89; H,
6.41; N, 9.22. Found: C, 36.39; H, 6.37; N, 9.18.
[0086] MS-EI: 455 (M.sup.+, 9%), 440 (M.sup.+-Me, 21%), 399
(M.sup.+-Me.sub.2C.dbd.CH.sub.2, 7%),
384(M.sup.+-Me-Me.sub.2C.dbd.CH.sub.2, 5%), 328
(M.sup.+-Me-2.Me.sub.2C.dbd.CH.sub.2, 5%), 58 (100%)
[0087] .sup.1H-NMR (CD.sub.6, 300 MHz, 300 K): 6.07 (bs, 2H,
CH-D.sup.tBuAD), 1.47 (s, 9H, N.sup.tBu), 1.35 (s, 18H),
.sup.tBu-D.sup.tBuAD)
[0088] .sup.13C{.sup.1H}-NMR (C.sub.6D.sub.6, 75 MHz, 300 K): 103.8
(CH-D.sup.tBuAD), 65.7 (NCMe.sub.3), 56.9 (CMe.sub.3-D.sup.tBuAD),
33.8 (NCMe.sub.3), 31.1 (CMe.sub.3-D.sup.tBuAD)
[0089] IR (KBr, cm.sup.-1): 3036(w), 1503(w), 1456(s), 1364(s),
1356(w), 1285(s), 1217(s), 1146(m), 1113(w), 1069(w), 1038(w),
1026(w), 1018(w), 964(w), 870(m), 810(m), 770(s), 723(w), 567(w),
544(w), 511(w), 453(w).
INTERMEDIATE EXAMPLE D
Production of [(D.sup.tBuAD)(.sup.tBuN)Nb(.mu.-Cl)].sub.2
[0090] 500 mg of the pyridine complex from Example 19 were
sublimated at 150.degree. C./10.sup.-4 mbar. Yield: 230 mg (56%).
Melting point 188.degree. C. Analysis analogous to intermediate
Example E.
INTERMEDIATE EXAMPLE E
Production of [(D.sup.tBuAD)(.sup.tBuN)Nb(.mu.-Cl)].sub.2
[0091] 23.2 ml of tert-butylamine (222 mmol) were added dropwise at
0.degree.C. with stirring to a suspension of 20.00 g of NbCl.sub.5
(74 mmol) in 300 ml of CH.sub.2Cl.sub.2. The reaction mixture was
heated to 23.degree. C. and stirred for 3 h at this temperature.
Then 12.5 g (74 mmol) of D.sup.tBuAD were added and the resulting
suspension was stirred for 8 h. The mixture was then filtered
following the addition of 150 ml of hexane. The volatile components
were removed from the filtrate at 20 mbar and the residue then
dissolved in 200 ml of THF. 1.0 g (148 mmol) of lithium powder were
then added slowly with cooling. After stirring for 8 h the solvent
was evaporated off at 20 mbar and the residue extracted twice with
150 ml of diethyl ether each time. The solvent was evaporated off
from the extract at 20 mbar. The residue was sublimated at
160.degree. C./10.sup.-4 mbar. Yield: 12.9 g (47% of theoretical),
melting point 188.4.degree. C.
[0092] Elemental analysis: Calculated (%) for monomeric
C.sub.14H.sub.29N.sub.3ClNb (M=367.77 g mol.sup.-1): C, 45.72; H,
7.95; N, 11.43. Found (%): C, 45.88; H, 8.04; N, 11.41.
[0093] MS-EI: 367(M.sup.+, 1%), 352(M.sup.+-Me, 1%),
296(M.sup.+-Me.sub.2C.dbd.CH.sub.2-Me, 0 1%), 58(100%).
[0094] .sup.1H-NMR (C.sub.6D.sub.6, 300 MHz, 300 K): 6.08 (broad s,
2H, CH-D.sup.tBuAD), 1.45 (s, 9H, N.sup.tBu), 1.38 (s, 18H,
.sup.tBu-D.sup.tBuAD).
[0095] .sup.13C{.sup.1H}-NMR (C.sub.6D.sub.6, 75 MHz, 300 K): 106.0
(CH-D.sup.tBuAD), 57.7 (CMe.sub.3-D.sup.tBuAD), 32.4 (NCMe.sub.3),
30.8 (CMe.sub.3-DAD).
[0096] IR (KBr, cm.sup.-): 3032(w), 1491(w), 1456(s), 1393(w),
1360(m), 1263(s), 1246(w), 1215(s), 1155(w), 1144(w), 1092(w),
1061(w), 1036(w), 1026(w), 1017(w), 951(w), 870(m), 810(m), 774(s),
723(w), 698(w), 669(w), 584(w), 569(m), 540(w), 515(w).
EXAMPLES ACCORDING TO THE INVENTION
Example 1
Production of (D.sup.tBuAD)(.sup.tBuN)TaCl as Pyridine Complex
[0097] A solution of 1.76 g (9.7 mmol) of Li.sub.2D.sup.tBuAD from
intermediate example A in 20 ml of THF was added dropwise at
-80.degree. C. to a solution of 5.00 g (9.7 mmol) of
.sup.tBuN.dbd.TaCl.sub.3.2Py (produced according to Lit. J.
Sundermeyer, J. Putterlik, M. Foth, J. S. Field, N. Ramesar, Chem.
Ber. 1994, 127, 1201-1212) in 20 ml of THF. After stirring for 30
min the dark-brown reaction mixture was heated and stirred for a
further 10 h at 23.degree. C. After distilling off all volatile
components the residue was extracted twice with 10 ml of diethyl
ether each time. The ether phases were combined, the ether
distilled off and the yellow residue washed twice with 10 ml of
hexane each time. Yield 2.11 g; in addition, a further 0.64 g were
obtained by crystallising the mother liquor at -80.degree. C. Total
yield 2.75 g (53.1% of theoretical), melting point 142.8.degree.
C.
[0098] Elemental analysis: Calculated (%) for
C.sub.19H.sub.34N.sub.4ClTa (M=534.91 gmol.sup.-1): C, 42.66; H,
6.41; N, 10.47. Found (%): C, 42.27; H, 5.97; N, 10.19.
[0099] MS-EI: 455 (M.sup.+Py, 15%), 440 (M.sup.+Py-Me, 39%), 399
(M.sup.+-Py-Me.sub.2C.dbd.CH.sub.2, 13%), 384
(M.sup.+-Py-Me-Me.sub.2C.dbd.CH.sub.2, 2%), 343
(M.sup.+-Py-2.Me.sub.2C.dbd.CH.sub.2, 1%) 328
(M.sup.+-Py-Me-2.Me.sub.2C.dbd.CH.sub.2, 7%), 287
(M.sup.+-Py-3.Me.sub.2C.dbd.CH.sub.2, 11% (Py.sup.+, 100%)
[0100] .sup.1H-NMR (.delta. against TMS, C.sub.6D.sub.6, 300 MHz,
300 K): 8.57 (d, .sup.3J.sub.HH=4.9 Hz, 2H, o-Py), 6.77 (t,
.sup.3J.sub.HH =7.7 Hz, 1H, p-Py), 6.45 (pseudo-t,
.sup.3J.sub.HH=6.7 Hz, 2H, m-Py), 6.17(broad s, 2H,
CH-D.sup.tBuAD), 1.55 (s, 9H, .sup.tBuN), 1.34 (broad s, 18H,
.sup.tBu-D.sup.tBuAD)
[0101] .sup.13C{.sup.1H}-NMR (C.sub.6D.sub.6, 75 MHz, 300 K):
150.7, 137.5 and 124.0 (Py), 65.5 (CMe.sub.3N), 56.6
(CMe.sub.3-D.sup.tBuAD), 34.2 (NCMe.sub.3), 30.9
(CMe.sub.3-D.sup.tBuAD)
[0102] .sup.13C{.sup.1H}-NMR (d.sub.8-toluene, 400 MHz, 230 K):
152.9, 139.9 and 126.8 (Py), 111.8 and 101.4 (CH-D.sup.tBuAD), 68.1
(NCMe.sub.3), 59.0 and 58.8(CMe.sub.3-D.sup.tBuAD), 36.7
(NCMe.sub.3), 33.5 and 33.0 (CMe.sub.3-D.sup.tBuAD)
[0103] IR (KBr, cm.sup.-1): 3075(w), 3040(w), 1604(w), 1504(w),
1458(s), 1444(m), 1359(m), 1354(m), 1275(s), 1251(w), 1217(s),
1145(m), 1145(w), 1064(w), 1045(w), 1012(w), 871(w), 814(w),
771(m), 761(m), 723(w), 698(m), 636(w), 567(w), 538(w), 507(w).
Example 2
Production of (D.sup.tBuAD)(.sup.tBuN)Ta(NH.sup.tBu) from
[(.sup.tBuN)(.sup.tBuNH)TaCl.sub.2(.sup.tBuNH.sub.2)].sub.2
[0104] 1.26 g of D.sup.tBuAD (7.5 mmol) were added to the yellow
solution of 3.50 g (3.7 mmol) of
[(.sup.tBuN)(.sup.tBuNH)TaCl.sub.2(.sup.tBuNH.sub.2)].sub.2
(produced according to Lit. K. C. Javaratne, G. P. A. Yap, B. S.
Haggerty, A. L. Rheingold, C. H. Winter, Inorg. Chem. 1996, 35,
4910-4920) in 40 ml of THF. The mixture was then stirred for
approx. 30 min at 23.degree. C. 0.19 g (7.8 mmol) of magnesium
powder were then added and stirred for a further 10 h at 23.degree.
C. Following complete dissolution of the Mg the THF was drawn off
at 20 mbar and the remaining yellow oil extracted twice with 25 ml
of hexane. After evaporating off the hexane, sublimation at
80.degree. C./10.sup.-2 mbar resulted in the product as a pale
yellow solid. Yield: 1.54 g (60% of theoretical), melting point
70.degree. C.
[0105] Analysis:
[0106] .sup.tH-NMR (C.sub.6D.sub.6, 300 MHz, 300 K): 5.62 (s, 2H,
CH-D.sup.tBuAD), 3.41 (s, 1H, NH), 1.56 (s, 9H, N.sup.tBu), 1.32
(s, 18H, .sup.tBu-D.sup.tBuAD), 1.27 (s, 9H, NH.sup.tBu)
[0107] .sup.13C{.sup.1H}-NMR (C.sub.6D.sub.6, 75 MHz, 300 K): 102.6
(CH-D.sup.tBuAD), 64.9 (NCMe.sub.3), 55.7 (CMe.sub.3-D.sup.tBuAD),
53.5 (NHCMe.sub.3), 35.3 (NCMe.sub.3),35.2(NHCMe.sub.3), 32.0
(CMe.sub.3-D.sup.tBuAD)
[0108] IR (KBr, cm.sup.-1): 3246(w), 3030(w), 1504(w), 1456(s),
1388(w), 1361(s), 1352(m), 1280(s), 1221(s), 1140(m), 1107(w),
1072(w), 1037(w), 1024(w), 985(m), 960(w), 920(w), 870(m), 816(w),
781(w), 771(m), 756(w), 590(w), 567(m), 527(m), 445(w).
Example 3
Production of (D.sup.tBuAD)(.sup.tBuN)Ta(NH.sup.tBu) from
(.sup.tBuN)(.sup.tBuNH)TaCl.sub.2.2Py
[0109] Instead of
[(.sup.tBuN)(.sup.tBuNH)TaCl.sub.2(.sup.tBuNH.sub.2)].sub.2,
(.sup.tBuN)(.sup.tBuNH)TaCl.sub.2.2PY (2.05 g=3.7 mmol,
intermediate example B) was used as the starting material with an
otherwise identical procedure. Yield 1.22 g=67% of theoretical,
melting point 70.degree. C.
[0110] Elemental analysis: Calculated (%) for
C.sub.18H.sub.39N.sub.4Ta (M=492.49 g mol.sup.-1): C, 43.90; H,
7.98; N, 11.3. Found (%): C, 42.56;.H, 7.89; N, 10.88.
[0111] MS-EI: 492 (M.sup.+, 33%), 477 (M.sup.+-Me, 100%), 436
(M.sup.+-Me.sub.2C.dbd.CH.sub.2, 10%), 421
(M.sup.+Me-Me.sub.2C.dbd.CH.sub.2, 10%), 380
(M.sup.+-2.Me.sub.2C.dbd.CH.sub.2, 1%), 365
(M.sup.+-Me-2.Me.sub.2C.dbd.CH.sub.2, 2%), 309
(M.sup.+-Me-3.Me.sub.2C.dbd.CH.sub.2, 1%)
[0112] Other spectroscopic data (.sup.1H-NMR, .sup.13C
{.sup.1H}-NMR and IR) as in Example 2.
Example 4
Production of (D.sup.tBuAD)(.sup.tBuN)Ta(NH.sup.tBu) (Direct
Synthesis from TaCl.sub.5)
[0113] 145.84 ml of tert-butylamine (1.40 mol) were added dropwise
with cooling to a suspension of 50.0 g of TaCl.sub.5 (139.58 mmol)
in 500 ml of toluene. After stirring for 8 h at 23.degree. C. the
yellow solution was filtered and the solvent drawn off at 20 mbar.
The oily intermediate was dissolved in 250 ml of THF with no
further purification, then 23.49 g (139.6 mmol) of D.sup.tBUAD,
followed by 3.39 g of Mg powder (139.6 mmol), were added. The
reaction mixture was stirred for 12 h at 23.degree. C., then the
solvent was drawn off at 20 mbar. The double extraction of the
residue with 150 ml of hexane each time produced a yellow, oily raw
product which was purified by sublimation at 80.degree. C./10-2
mbar. Yield 35.7 g (52% of theoretical), melting point 70.degree.
C.
[0114] Spectroscopic data (.sup.tH-NMR, .sup.13C {.sup.1H}-NMR and
IR) as in Example 2.
Example 5
Production of (D.sup.tBuAD)(.sup.tBuN)Ta(O.sup.tBu) from
(D.sup.tBuAD)(.sup.tBuN)Ta(NH.sup.tBu)
[0115] A solution of 0.75 g of tert-butanol (10.15 mmol) in 100 ml
of hexane was added dropwise to a solution of 5.00 g (10.15 mmol)
of (D.sup.tBuAD)(.sup.tBuN)Ta(NH.sup.tBu) from Example 2 in 100 ml
of hexane at -80.degree. C. The reaction mixture was then stirred
for 3 h at 23.degree. C. The solvent was drawn off at 20 mbar and
the colourless product sublimated at 100.degree. C./10.sup.-2 mbar.
Yield: 4.65 g (93% of theoretical), melting point 79.degree. C.
[0116] Elemental analysis: Calculated (%) for
C.sub.18H.sub.39N.sub.3OTa (M=493.47 g mol-.sup.-1): C, 43.81; H,
7.76; N, 8.52. Found (%): C, 42.89; H, 7.88; N, 8.29.
[0117] MS-EI: 493 (M.sup.+, 44%), 478 (M.sup.+-Me, 21%), 437
(M.sup.+-Me.sub.2C.dbd.CH.sub.2, 5%), 422
(M.sup.+-Me-Me.sub.2C.dbd.CH.sub.2, 100%), 381
(M.sup.+-2.Me.sub.2C.dbd.CH.sub.2, 60%), 366
(M.sup.+-Me-2.Me.sub.2C.dbd.CH.sub.2, 5%), 310 (M.sup.+-Me
3.Me.sub.2C.dbd.CH.sub.2, 2%)
[0118] .sup.1H-NMR (.delta. against TMS, C.sub.6D.sub.6, 300 MHz,
300 K): 5.82 (s, 2H, CH-D.sup.tBuAD), 1.54 (s, 9H, N.sup.tBu), 1.33
(s, 9H, O.sup.tBu), 1.32 (s, 18H, .sup.tBu-D.sup.tBuAD)
[0119] .sup.13C{.sup.1H}-NMR (C.sub.6D.sub.6, 75 MHz, 300 K): 104.4
(CH-DAD), 55.9 (CMe.sub.3-D.sup.tBuAD), 35.3 (s, NCMe.sub.3), 33.3
(OCMe.sub.3), 32.0 (CMe.sub.3-D.sup.tBuAD)
[0120] IR: (.upsilon., cm.sup.-1) 3034(w), 1586(w), 1361(s),
1286(s), 1261(w), 1223(s), 1188(s), 1142(m), 1072(w), 1008(s),
959(w), 920(w), 869(m), 806(m), 789(m), 772(m), 722(w), 563(w),
529(w), 514(w), 471(w).
Example 6
Production of (D.sup.tBuAD)(.sup.tBuN)Ta(O.sup.tBu) from
(D.sup.tBuAD)(.sup.tBuN)TaCl(Py)
[0121] 42 mg (0.37 mmol) of .sup.tBuOK in 10 ml of THF were added
to 200 mg (0.37 mmol) of (D.sup.tBuAD)(.sup.tBuN)TaCl(Py) from
Example 1 in 10 ml of TBF at -80.degree. C. After stirring for 5 h
at 23.degree. C. the solvent was distilled off at 20 mbar. The
brown, oily residue was sublimated at 100.degree. C./10.sup.-2 mbar
and produced 95 mg of product (52% of theoretical) with a melting
point of 79.degree. C.
[0122] Spectroscopic data (.sup.1H-NMR, .sup.13C-NMR, IR) identical
to Example 5.
Example 7
Production of (D.sup.tBuAD)(.sup.tBuN)Ta(AcAc) from
(D.sup.tBuAD)(N.sup.tBu)Ta(NH.sup.tBu)
[0123] 0.20 g of acetyl acetone (2.0 mmol), dissolved in 10 ml of
hexane, were added to a solution of 1.00 g (2.0 mmol) of
(D.sup.tBuAD)(.sup.tBuN)Ta(NH.sup.tBu) from Example 4 in 10 ml of
hexane at -80.degree. C. The reaction mixture was then stirred for
5 h at 23.degree. C. After distilling off the solvent at 20 mbar
0.97 g (92% of theoretical) of the analytically pure product were
isolated as an orange-coloured powder, melting point 99.1.degree.
C.
[0124] MS-EI: 519 (M.sup.+, 74%), 504 (M.sup.+-Me, 43%), 448
(M.sup.+-Me.sub.2C.dbd.CH.sub.2, 3%), 57 (.sup.tBu.sup.+, 100%)
[0125] .sup.1H-NMR (.delta. against TMS, C.sub.6D.sub.6, 300 MHz,
300 K): 6.04 (s, 2H, CH-D.sup.tBuAD), 5.06 (s, 1H CH--AcAc), 1.60
(s, 6H, Me-AcAc), 1.56 (s, 18H, .sup.tBu-D.sup.tBuAD), 1.47 (s, 9H,
N.sup.tBu)
[0126] .sup.13C{.sup.1H}-NMR (C.sub.6D.sub.6, 75 MHz, 300 K): 191.7
(CO--AcAc), 103.6 (CH--AcAc), 103.4 (CH-D.sup.tBuAD), 55.7
(CMe.sub.3-D.sup.tBuAD), 54.2 (NCMe.sub.3), 34.3 (NCMe.sub.3), 31.5
(CMe.sub.3-D.sup.tBuAD), 26.1 (Me-AcAc)
[0127] IR(KBr, cm.sup.-1): 1590(m), 1530(m), 1281(m), 1262(w),
1223(m), 1137(w), 1093(w), 1026(w), 968(w), 933(w), 861(w), 804(w),
762(w), 722(w), 665(w), 566(w), 534(w), 432(w).
Example 8
Production of (D.sup.tBuAD)(.sup.tBuN)Ta(AcAc) from
(D.sup.tBuAD)Ta(N.sup.tBu)Cl(Py)
[0128] 640 mg (1.2 mmol) of (D.sup.tBuAD)Ta(N.sup.tBu)Cl(Py) from
Example 1 were dissolved in 15 ml of THF. To this was added a
suspension of 146 mg (1.2 mmol) of sodium acetyl acetonate in 10 ml
of THF at -80.degree. C. After heating to 23.degree. C. and
stirring for 10 h at this temperature, the solvent was distilled
off at 20 mbar. The brown, oily residue was extracted with hexane
and crystallised out of hexane, producing 0.28 g (50% of
theoretical) of orange-coloured crystals with a melting point of
99.degree. C.
[0129] Analysis: Spectroscopic data (MS, .sup.1H-NMR, .sup.13C-NMR
and IR) identical to Example 8.
Example 9
Production of (D.sup.tBuAD)(.sup.tBuN)TaBz as Pyridine Complex
[0130] A suspension of 210 mg of benzyl magnesium chloride THF
complex (0.94 mmol) in 10 ml of diethyl ether was added to 500 mg
(0.94 mmol) of [(D.sup.tBuAD)(.sup.tBuN)TaCl(Py)] from Example 1,
dissolved in 10 ml of diethyl ether, at -80.degree. C. After 10 min
the orange-coloured reaction mixture was heated to 23.degree. C.
and stirred at this temperature for 5 h. The yellow precipitate
that was formed was then filtered off and washed with 5 ml of
diethyl ether. Iirying and subsequent recrystallisation from hexane
produced 210 mg (38% of theoretical) of pure product as
orange-coloured crystals, melting point 117.7.degree. C.
[0131] MS-EI: 511 (M.sup.+-Py, 3%), 52 (100%)
[0132] .sup.1H-NMR (.delta. against TMS, C.sub.6D.sub.6, 300 MHz,
300 K): 8.21 (d, .sup.3.sub.J.sub.HH=3.1 Hz, 2H, o-Py), 6.91 (t,
.sup.3J.sub.HH=7.6 Hz, 1H, m-Bz), 6.72-6.62 (m, 4H, o- and p-Bz
overlapped with p-Py), 6.30 (pseudo-t, .sup.3J.sub.HH=6.7 Hz, 2H,
m-Py), 6.06 (s, 2H, CH--D.sup.tBuAD), 2.10 (broad s, 2H,
CH.sub.2-Bz), 1.58 (s, 9H, N.sup.tBu), 1.26 (broad s, 18H,
.sup.tBu-DAD)
[0133] .sup.13C {.sup.1H}-NMR (C.sub.6D.sub.6, 75 MHz, 300 K):
153.8 (C.sub.i-Bz), 150.2 (o-Py), 136.7 (p-Py), 127.2 (m-Bz), 126.5
(o-Bz), 123.8 (m-Py), 119.5 (p-Bz), 104.8 (CH-D.sup.tBuAD), 65.5
(NCMe.sub.3), 56.3 (CMe.sub.3-D.sup.tBuAD), 53.6 (CH.sub.2-Bz),
34.8 (NCMe.sub.3), 31.2 (Ce3-D.sup.tBuAD)
[0134] IR (KBr, cm.sup.-1): 3057(w), 1602(w), 1591(w), 1361(w),
1276(m), 1262(w), 1218(m), 1172(w), 1152(w), 1137(w), 1094(w),
1071(w), 1058(w), 1040(w), 1028(w), 1014(m), 986(w), 960(w),
867(w), 805(m), 764(w), 747(w), 723(w), 693(w), 631(w), 592(w),
557(w), 538(w), 503(w).
Example 10
Production of (D.sup.tBuAD)(.sup.tBuN)TaBz from
(D.sup.tBuAD)(.sup.tBuN)Ta(O.sup.tBu)
[0135] 0.50 g (1.0 mmol) of (D.sup.tBuAD)(.sup.tBuN)Ta(O.sup.tBu)
from Example 6 and 0.22 g (1.0 mmol) of benzyl magnesium chloride
THF complex (BzMgCl*THF) were mixed at 23.degree. C. This mixture
of solids was dissolved in 20 ml of THF and the solution obtained
was stirred for 12 h at 23.degree. C. THF was then removed in vacuo
(rotary evaporator) and the remaining oil extracted with 10 ml of
hexane. Hexane was distilled off and the product distilled
(150.degree. C./10.sup.-4 mbar). Yield: 0.14 g (27%) as a light
yellowish liquid.
[0136] MS-EI: 511 (M.sup.+, 23%), 496 (M.sup.+-Me, 32%), 420
(M.sup.+-Bz, 5%), 363 ([D.sup.tBuAD)TaN]hu +, 13%), 57
(.sup.tBu.sup.+, 100%)
[0137] .sup.1H-NMR (C.sub.6D.sub.6, 200 MHz, 300 K): 7.22-6.90 (m,
5H, Bz), 5.66 (s, 2H, CH-D.sup.tBuAD), 2.01 (s, 2H, CH.sub.2-Bz),
1.62 (s, 9H, N.sup.tBu), 1.18 (s, 18H, .sup.tBu-D.sup.tBuAD)
[0138] .sup.13C{.sup.1H}-NMR (C.sub.6D.sub.6, 50 MHz, 300 K):
143.2, 128.4, 127.4 and 122.4 (arom. Bz), 103.1 (CH-D.sup.tBuAD),
65.4 (NCMe.sub.3), 57.6 (CH.sub.2-Bz), 57.1
(CMe.sub.3-D.sup.tBuAD), 35.0 (NCMe.sub.3), 31.3
(CMe.sub.3-D.sup.tBuAD).
[0139] IR (KBr, cm.sup.-1): 3071(w), 3051(w), 3015(m), 2965(s),
2940(s), 2924(s), 2897(s), 2866(m), 1593(s), 1483(s), 1470(m),
1456(m), 1402(w), 1391(m), 1375(m), 1363(s), 1354(s), 1283(s),
1221(s), 1179(w), 1138(s), 1107(w), 1076(w), 1030(m), 1018(m),
993(w), 963(m), 872(s), 820(m), 808(w), 787(w), 777(s), 747(s),
694(s), 625(w), 565(m), 523(s), 451(m).
Example 11
Production of (DtBD)(.sup.tBuN)TaBz from
[(D.sup.tBuAD)(.sup.tBuN)Ta(.mu.-Cl)].sub.2
[0140] Instead of (D.sup.tBuAD)(.sup.tBuN)Ta(O.sup.tBu), 0.46 g of
[(D.sup.tBuAD)(.sup.tBuN)Ta(.mu.-Cl)].sub.2 from intermediate
Example C (1.00 mmol, calculated as monomeric compound) were used
as the starting material with otherwise the same procedure as in
Example 14. Yield 1.22 g=74% of theoretical.
[0141] Analytical data (MS, .sup.1H-NMR, .sup.13C-NMR, IR)
identical to Example 10.
Example 12
Production of (D.sup.tBuAD)(.sup.tBuN)TaCp from
(D.sup.tBuAD)(N.sup.tBu)TaCl(Py)
[0142] A solution of 40 mg of cyclopentadienyl lithium (0.56 mmol)
in 5 ml of THF was added dropwise to 300 mg (0.56 mmol) of
(D.sup.tBuAD)(N.sup.tBu)TaCl(Py) from Example 1 in 5 ml of THF at
-80.degree. C. At the end of the addition the reaction mixture was
heated to 23.degree. C. and stirred for a further 3 h at this
temperature. The THF was then distilled off at 20 mbar and the
dark, oily residue extracted twice with 15 ml of hexane.
Recrystallisation with hexane and subsequent sublimation at
90.degree. C. and 10.sup.-2 mbar produced 130 mg (48% of
theoretical) of analytically pure product with a melting point of
65.3.degree. C.
[0143] Elemental analysis: Calculated (%) for
C.sub.19H.sub.34N.sub.3Ta (M=485.45 g mol.sup.-1): C, 47.01; H,
7.06; N, 8.66. Found (%): C, 45.03; H, 7.06; N, 7.93.
[0144] MS-EI: 485 (M.sup.+, 55%), 470 (M.sup.+-Me, 100%), 429
(M.sup.+-Me.sub.2C.dbd.CH.sub.2, 2%), 414
(M.sup.+-Me-Me.sub.2C.dbd.CH.sub.2, 16%), 373
(M.sup.+-2.Me.sub.2C.dbd.CH.sub.2, 2%), 358
(M.sup.+-Me-2.Me.sub.2C.dbd.CH.sub.2, 8%), 317
(M.sup.+-3.Me.sub.2C.dbd.CH.sub.2, 10%),
302(M.sup.+-Me-3.Me.sub.2C.dbd.CH.sub.2, 3%)
[0145] .sup.1H-NMR (.delta. against TMS, C.sub.6D.sub.6, 300 MHz,
300 K): 5.67 (s, 2H, CH-D.sup.tBuAD), 5.66 (s, 5H, C.sub.5H.sub.5),
1.30 (s, 9H, N.sup.tBu), 1.25 (s, 18H, .sup.tBu-D.sup.tBuAD)
[0146] .sup.13C{.sup.1H}-NMR (C.sub.6D.sub.6, 75 MHz, 300 K): 108.3
(CH-D.sup.tBuAD), 100.8 (C.sub.5H.sub.5), 55.5
(CMe.sub.3-D.sup.tBuAD), 34.1 (NCMe.sub.3), 31.9
(CMe.sub.3-D.sup.tBuAD)
[0147] IR (KBr, cm.sup.-): 3028(w), 1506(w), 1358(m), 1274(s),
1221(s), 1156(w), 1095(w), 1061(w), 1013(w), 958(w), 865(w),
795(s), 766(m), 722(w).
Example 13
Production of (D.sup.tBuAD)(.sup.tBuN)TaCp from
CpTa(N.sup.tBu)Cl.sub.2
[0148] A solution of 940 mg of Li.sub.2D.sup.tBuAD (5.15 mmol) in
20 ml of THF was added dropwise to 2.00 g (5.15 mmol) of
CpTa(N.sup.tBu)Cl.sub.2 (produced according to Lit. S. Schmidt, J.
Sundermeyer, J. Organomet. Chem. (1994), 472(1-2), 127-38) in 20 ml
of THF at -80.degree. C. At the end of the dropwise addition, the
batch was heated to 23.degree. C. by removing the cooling and
stirred at this temperature for 8 h. The THF was then drawn off at
20 mbar and the product extracted with 30 ml of hexane. Sublimation
at 120.degree. C./0.01 mbar produced 500 mg (20.0% of theoretical)
of (D.sup.tBuAD)(.sup.tBuN)TaCp as a yellow solid.
[0149] Spectroscopic data (.sup.1H-, .sup.13C-NMR and IR spectra)
identical to Example 12.
Example 14
Production of (D.sup.tBuAD)(.sup.tBuN)TaInd
[0150] A solution of indenyl lithium (114 mg, 0.93 mmol) in 10 ml
of THF was added to 500 mg of (D.sup.tBuAD)(.sup.tBuN)TaCl(Py)
(0.93 mmol) from Example 1 in 10 ml of THF at -80.degree. C. and
the reaction mixture was then stirred for 8 h at 23.degree. C. THF
was distilled off at 20 mbar and the complex extracted twice with
15 ml of hexane each time. Removing the hexane by distillation at
20 mbar produced 300 mg (60% of theoretical) of the analytically
pure product. Melting point 147.3.degree. C.
[0151] Elemental analysis: Calculated (%) for
C.sub.23H.sub.36N.sub.3Ta (M=535.51 g mol.sup.-1): C, 51.59; H,
6.78; N, 7.85. Found (%): C, 50.39; H, 6.79; N, 7.56.
[0152] MS-EI: 535 (M.sup.+, 44%), 520 (M.sup.+-Me, 87%), 464
(M.sup.+-Me-Me.sub.2C.dbd.CH.sub.2, 7%), 367
(M.sup.+-3-Me.sub.2C.dbd.CH.sub.2, 4%), 352
(M.sup.+-Me-3.Me.sub.2C.dbd.CH.sub.2, 3%), 57 (.sup.tBu.sup.+,
100%)
[0153] .sup.1H-NMR (.delta. against TMS, C.sub.6D.sub.6, 300 MHz,
300 K): 7.17 (d, 2H, J.sub.H-H=2.9 Hz, Ind), 6.92 (t, 1H,
J.sub.H-H=3.2 Hz, Ind), 6.92 (dd, 2H, J.sub.H-H=3.2 Hz,
J.sub.H-H=2.9 Hz, Ind), 6.14 (d, 2H, J.sub.H-H=3.2 Hz, Ind), 5.11
(s, 2H, CH-D.sup.tBuAD), 1.28 (s, 27H, N.sup.tBu overlapping with
.sup.tBu-D.sup.tBuAD)
[0154] .sup.13C{.sup.1H}-NMR (C.sub.6D.sub.6, 75 MHz, 300 K):
123.1, 122.8 and 110.6 (Ind), 107.4 (CH-D.sup.tBuAD), 84.8 (Ind),
64.5 (NCMe.sub.3), 55.8 (CMe.sub.3-D.sup.tBuAD), 34 (NCMe.sub.3),
31.8 (CMe.sub.3-D.sup.tBuAD)
[0155] IR (KBr, cm.sup.-): 3075(w), 3038(w), 1504(w), 1464(s),
1360(m), 1329(w), 1279(s), 1248(w), 1221(s), 1157(w), 1095(w),
1064(w), 1038(w), 1026(w), 932(w), 868(m), 814(m), 783(s), 771(m),
740(w), 735(m), 600(w), 559(w).
Example 15
Production of (D.sup.tBuAD)(DipN)Ta(NHDip)
[0156] A solution of 0.72 g of DipNH.sub.2 (4.0 mmol) in 10 ml of
hexane was added dropwise to a solution of 1.00 g (2.0 mmol) of
(D.sup.tBuAD)(.sup.tBuN)Ta(NH.sup.tBu) from Example 2 in 10 ml of
hexane at 0.degree.C. The reaction mixture was stirred for 24 h at
23.degree. C. The solution was then concentrated by evaporation to
5 ml and left to stand. After separating off the first crystals the
solution was cooled to -30.degree. C., causing the product to
crystallise out. Filtration produced 0.64 g (45% of theoretical) of
product with a melting point of 149.8.degree. C.
[0157] Elemental analysis: Calculated (%) for
C.sub.34H.sub.55N.sub.4Ta (M=700.79 g mol.sup.-1): C, 58.27; H,
7.91; N, 7.99. Found (%): C, 57.43; H, 7.93; N, 7.90.
[0158] MS-EI: 700 (M.sup.+, 100%), 524 (M.sup.+-DipNH, 56%)
[0159] .sup.1H-NMR (.delta. against TMS, C.sub.6D.sub.6, 300 MHz,
300 K): 7.19-6.92 (m, 6H, Dip), 5.67 (s, 2H, CH-D.sup.tBuAD), 4.69
(broad s, 1H, NH), 3.97 and 3.47 (sept, 2H, .sup.3J.sub.HH+6.7 Hz,
CH-DipN and CH-DipNH) 1.27 (s, 18H, .sup.tBu-D.sup.tBuAD), 1.24 and
1.22 (d, 12H, .sup.3J.sub.HH=6.7 Hz, CH.sub.3-DipN overlapping with
CH.sub.3-DipNH)
[0160] .sup.13C{.sup.1H}-NMR (C.sub.6D.sub.6, 75 MHz, 300 K):
145.8, 142.8, 141.0, 123.7, 122.9, 122.5 and 122.0 (arom. DipNH and
DipN), 102.9 (CH-D.sup.tBuAD), 57.9 (CMe.sub.3-D.sup.tBuAD), 31.1
(CMe.sub.3-D.sup.tBuAD), 29.2 and 27.9 (CH-DipNH and CH-DipN), 24.4
and 23.6 (CH.sub.3-DipNH and CH.sub.3-DipN)
[0161] IR (KBr, cm.sup.-1): 3270(m), 3048(w), 3032(w), 1620(w),
1588(w), 1431(m), 1364(s), 1323(w), 1296(w), 1251(w), 1221(s),
1159(w), 1142(m), 1115(w), 1099(w), 1074(w), 1057(w), 1045(w),
1024(w), 988(m), 963(w), 934(w), 889(w), 876(m), 864(w), 818(w),
802(w), 797(w), 777(w), 770(w), 750(m), 723(w), 698(w), 583(w),
567(w), 521(w), 446(w).
Example 16
Production of (D.sup.tBuAD)(.sup.tBuN)Ta(BH.sub.4)
[0162] 2.00 g (4.39 mmol, calculated as monomeric compound) of
[(D.sup.tBuAD) (.sup.tBuN)Ta(.mu.-Cl)].sub.2 from intermediate
example C and 0.17 g of NaBH4 (4.39 mmol) were suspended in 50 ml
of THF and stirred for 12 h at 23.degree. C. THF was distilled off
at 20 mbar and the product extracted with 20 ml of hexane. The
solvent was evaporated off from the extract and the remaining red
oil sublimated at 60.degree. C./10.sup.-4 mbar. The sublimation
produced 1.64 g (86% of theoretical) of pale yellow, solid product
with a melting point of 69.5.degree. C.
[0163] Elemental analysis: Calculated (%) for
C.sub.14H.sub.33BN.sub.3Ta (M=435.20 g mol.sup.-1): C, 38.64; H,
7.64; N, 9.66. Found (%):
[0164] C, 38.86; H, 7.71; N, 9.47.
[0165] MS-EI: 435 (M.sup.+, 11%), 420 (M.sup.+-Me, 7%), 406
(M.sup.+-Me-BH.sub.3, 13%), 378 (M.sup.+-H-Me.sub.2C.dbd.CH.sub.2,
5%), 365 (M.sup.+-BH.sub.3-Me.sub.2C.dbd.CH.sub.2, 2%), 58
(.sup.tBuH.sup.+, 100%)
[0166] .sup.1H-NMR (.delta. against TMS in C.sub.6D.sub.6, 500 MHz,
300 K): 5.91 (s, 2H, CH-D.sup.tBuAD), 1.73 (q, 4H,
.sup.1J.sub.BH=85 Hz, BH.sub.4), 1.41 (s, 9H, N.sup.tBu), 1.24 (s,
18H, .sup.tBu-D.sup.tBuAD)
[0167] .sup.13C{.sup.1H}-NMR (C.sub.6D.sub.6, 125 MHz, 300 K):
105.8 (CH-DAD), 65.8 (NCMe.sub.3), 57.0 (CMe.sub.3-D.sup.tBuAD),
34.5 (NCMe.sub.3), 31.8 (CMe.sub.3-D.sup.tBuAD)
[0168] .sup.11B--NMR (C.sub.6D.sub.5CD.sub.3, 160 MHz, 300 K):
+20.2 (pent, .sup.1J.sub.BH.sub.=85 Hz, BH4)
[0169] IR (KBr, cm.sup.-1): 3041(w), 2519(s), 2326(w), 2284(w),
2097(w), 2037(s), 1505(w), 1456(s), 1389(m), 1379(s), 1364(s),
1356(s), 1279(s), 1217(s), 1148(s), 1111(w), 1071(m), 1038(w),
1028(w), 961(m), 916(w), 874(s), 818(s), 810(w), 775(s), 723(w),
546(w).
Example 17
Production of (D.sup.tBuAD)(.sup.tBuN)Ta(.sup.72 .sup.3-all)
[0170] 1.00 g of [(D.sup.tBuAD)(.sup.tBuN)Ta(.pi.-Cl)].sub.2 (2.19
mmol, calculated as monomeric compound) from intermediate example C
and 0.48 g of allyl magnesium bromide THF complex (AllMgBr*THF)
(2.19 mmol) were dissolved in 20 ml of THF and stirred for 12 h at
23.degree. C. The solvent was then drawn off at 20 mbar. The
remaining yellow solid was extracted twice with 10 ml of hexane
each time. After removing the solvent in vacuo (20 mbar)
sublimation was performed at 80.degree. C./10.sup.-4 mbar. Yield:
0.74 g (73% of theoretical) of
(D.sup.tBuAD)(.sup.tBuN)Ta(.eta..sup.3-all) as a yellow solid with
a melting point of 61.9.degree. C.
[0171] Elemental analysis: Calculated (%) for
C.sub.17H.sub.34N.sub.3Ta (M=461.43 g mol-1): C, 44.25;H, 7.43;N,
9.11. Found (%): C, 43.81; H, 7.37; N, 9.04.
[0172] MS-EI: 461 (M.sup.+, 53%), 446 (M.sup.+-Me, 25%), 420
(M.sup.+-all, 22%), 363 ([(D.sup.tBuAD)(TaN]+, 21%), 57
(.sup.tBu.sup.+, 100%)
[0173] .sup.1H-NMR (.delta. against TMS in C.sub.6D.sub.6, 300 MHz,
300 K): 6.44 (pent, 1H, .sup.3J.sub.HH=11.4 Hz, .eta..sup.3-all),
5.50 (s, 2H, CH-DAD), 2.31 (broad s, 4H, .eta..sup.3-all), 1.36 (s,
18H, .sup.t Bu-D.sup.tBUAD), 1.26 (s, 9H, N.sup.tBu)
[0174] .sup.13C{.sup.1H}-NMR (C.sub.6D.sub.6, 75 MHz, 300 K): 133.0
(.eta..sup.3-all), 102.3 (CH-D.sup.tBuAD), 68.8 (.eta..sup.3-all),
65.4 (NCMe.sub.3) 56.2 (CMe.sub.3-D.sup.tBuAD) 34.4 (NCMe.sub.3),
31.8 (CMe.sub.3-D.sup.tBuAD)
[0175] IR (KBr, cm.sup.-1): 3065(w), 3027(m), 1628(w), 1501(m),
1456(s), 1389(m), 1360(s), 1281(s), 1248(w), 1221(s), 1150(m),
1109(w), 1063(w), 1016(w), 1003(m), 961(w), 866(m), 841(s), 808(m),
768(s), 723(w), 694(w), 629(w), 563(w).
Example 18
Production of a Ta-containing CVD Coating According to the
Invention
[0176] After conventional pretreatment a Si wafer (manufacturer:
Wacker or Virginia Semiconductor) was placed in a CVD apparatus
(Aix 200 from Aixtron AG). First of all a thermal curing step was
performed on the Si wafer in the conventional way for purification
purposes at 750.degree. C. in an inert carrier gas stream. Then the
wafer was cooled to a substrate temperature of 350.degree. C. A
coating comprising the Ta starting substances according to the
invention was deposited onto the surface obtained in this way. To
this end an inert gas stream of N.sub.2 was loaded with the various
starting materials. The following were used as starting materials:
(DAD)(.sup.tBuN)Ta(BH.sub.4) and 1,1-dimethylhydrazine, the
1,1-dimethylhydrazine being commercially available in the
appropriate purity for CVD (for example from Akzo Nobel HPMO).
[0177] For the production of the Ta-containing coatings according
to the invention the following conditions were chosen, for example,
with an overall pressure of the CVD reactor of 100 hPa: 0.0005 hPa
(DAD)(.sup.tBuN)Ta(BH.sub.4), 3 hPa 1,1-dimethylhydrazine. The N/Ta
ratio was thus chosen as 6000. The loaded N.sub.2 carrier gas
stream with an overall pressure of 100 hPa was then passed over the
surface of the Si wafer heated to 350.degree. C. for a period of 1
h. A coating according to the invention with a thickness of 145 nm
was obtained. At the end of the exposure time the CVD plant was
adjusted to the deposition conditions for a desired further coating
or the coating was cooled under an inert carrier gas stream and
removed from the CVD reactor.
Example 19
Production of (D.sup.tBuAD)(.sup.tBuN)NbCl as Pyridine Complex
[0178] A solution of 2.1 g (11.7 mmol) of Li.sub.2D.sup.tBuAD from
intermediate example A in 20 ml of THF was added dropwise to a
solution of 5.0 g (11.7 mmol) of .sup.tBuN.dbd.NbCl.sub.3.2Py
(produced in accordance with Lit. J. Sundermeyer, J. Putterlik, M.
Foth, J. S. Field, N. Ramesar, Chem. Ber. 1994, 127, 1201-1212) in
20 ml of THF at -80.degree. C. After stirring for 30 min the
dark-brown reaction mixture was. heated and stirred for a further
10 h at 23.degree. C. After removing all volatile components by
distillation the residue was extracted twice with 10 ml of diethyl
ether each time. The ether phases were combined, the ether
distilled off and the yellow residue washed with 20 ml of hexane.
Yield 3.8 g (72% of theoretical), melting point 115.4.degree.
C.
[0179] Elemental analysis: Calculated (%) for
C.sub.19H.sub.34N.sub.4ClNb (M=446.87 gmol.sup.-1): C, 51.07; H,
7.67; N, 12.54. Found (%): C, 49.26; H, 7.64; N, 11.84.
[0180] MS-EI: 367 (M.sup.+-Py, 30%), 352 (M.sup.+-Py-Me, 46%), 296
(M.sup.+-Py-Me.sub.2C.dbd.CH.sub.2-Me, 3%), 240
(M.sup.+-Py-Me-2.Me.sub.2C.dbd.CH.sub.2, 2%), 199 (M.sup.+-Py
-3.Me.sub.2C.dbd.CH.sub.2, 13%),57 (100%).
[0181] .sup.1H-NMR (.delta. against TMS, C.sub.6D.sub.6, 300 MHz,
300 K): 8.53 (pseudo-d, .sup.3J.sub.HH=3.6 Hz, 2H, o-Py), 6.79
(pseudo-t, .sup.3J.sub.HH=7.6 Hz, 1H, p-Py), 6.47 (pseudo-t,
.sup.3J.sub.HH=6.3 Hz, 2H, m-Py), 6.17 (broad s, 2H,
CH-D.sup.tBuAD), 1.52 (s, 9H, .sup.tBuN), 1.35 (broad s, 18H,
.sup.tBu-D.sup.tBuAD)
[0182] .sup.1H-NMR (.delta. against TMS, d.sub.8-toluene, 100 MHz,
230 K): 8.39 (dd, .sup.3J.sub.HH=6.4 Hz, .sup.4J.sub.HH=1.5 Hz, 2H,
o-Py), 6.69 (tt, .sup.3J.sub.HH=7.6 Hz, .sup.4J.sub.HH=1.5 Hz, 1H,
p-pY), 6.38-6.35 (m, 3H, m-Py overlapping with CH-D.sup.tBuAD),
5.82 (d, 1H, .sup.3J.sub.HH=3.5 Hz, CH-D.sup.tBuAD), 1.64 (s, 9H,
.sup.tBu-D.sup.tBuAD), 1.51 (s, 9H, .sup.tBuN), 0.96 (broad s, 9H,
.sup.tBu-D.sup.tBuAD).
[0183] .sup.13C{.sup.1H}-NMR (C.sub.6D.sub.6, 75 MHz, 300 K):
150.6, 136.9 and 123.7-(Py), 57.3 (CMe.sub.3-D.sup.tBuAD), 32.9
(NCMe.sub.3), 30.7 (CMe.sub.3-D.sup.tBuAD).
[0184] .sup.13C{.sup.1H}-NMR (d.sub.8-toluene, 400 MHz, 230 K):
150.1, 137.7 and 123.9 (Py), 110.3 and 101.2 (CH-D.sup.tBuAD), 67.0
(NCMe.sub.3), 57.0 and 56.6 (CMe.sub.3-D.sup.tBuAD), 32.7
(NCMe.sub.3), 30.5 and 30.2 (CMe.sub.3-D.sup.tBuAD).
[0185] IR (KBr, cm.sup.-1): 3020(w), 1602(w), 1480(w), 1360(m),
1353(w), 1258(m), 1244(m), 1217(s), 1155(w), 1138(w), 1057(w),
1045(w), 1012(w), 875(m), 814(m), 775(m), 761(m), 723(w), 700(m),
634(w).
Example 20
Production of (D.sup.tBUAD)Nb(N.sup.tBu)BH.sub.4)
[0186] 1.6 g (4.35 mmol, calculated as monomeric compound) of
[(D.sup.tBuAD) (.sup.tBuN)Nb(.mu.-Cl)].sub.2 from intermediate
Example E and 0.37 g of NaBH.sub.4 (9.78 mmol) were suspended in 50
ml of THF and stirred for 12 h at 23.degree. C. The solvent was
distilled off at 20 mbar and the residue sublimated at 60.degree.
C./10.sup.-4 mbar. The sublimation produced 0.95 g (67% of
theoretical) of a yellow, solid product with a melting point of
65.4.degree. C.
[0187] Elemental analysis: Calculated (%) for
C.sub.14H.sub.33BN.sub.3Nb (M=347.16 g mol.sup.-1): C, 48.44; H,
9.58; N, 12.10. Found (%): C, 47.88; H, 9.56; N, 12.11.
[0188] MS-EI: 347 (M.sup.+, 100%), 332 (M.sub.+-Me, 8%), 318
(M.sup.+-Me-BH.sub.3, 13%), 276 (M.sup.+-Me.sub.2C.dbd.CH.sub.2-Me,
42%). .sup.1H-NMR (d.sub.8-toluene, 500 MHz, 300 K: 5.87 (s, 2H,
CH-D.sup.tBuAD), 1.31 (s, 9H, N.sup.tBu), 1.19 (s, 18H,
.sup.tBu-D.sup.tBuAD), 0.04 (q, 4H, .sup.1J.sub.BH=85 Hz,
BH.sub.4).
[0189] .sup.13C{.sup.1H}-NMR (CD.sub.6, 75 MHz, 300 K): 107.8
(CH-D.sup.tBuAD), 33.1 (NCMe.sub.3), 31.6 (CMe.sub.3-D.sup.tBuAD).
.sup.11B--NMR (d.sub.8-toluene, 160 MHz, 300 K): -21.3 (quint,
.sup.1J.sub.BH=85 Hz, BH.sub.4).
[0190] IR (KBr, cm.sup.-1): 3032(w), 2507(s), 2319(w), 2274(w),
2099(w), 2037(s), 1495(w), 1456(s), 1390(w), 1364(s), 1302(w),
1258(s), 1217(s), 1157(s), 1140(w), 1111(w), 1061(w), 1026(w),
1017(w), 947(w), 876(s), 816(s), 777(s), 723(w), 567(w), 516(w),
513(w), 494(w), 449(w).
Example 21
Production of (D.sup.tBuAD)Nb(N.sup.tBu)(NH.sup.tBu)
[0191] 225 ml of tert-butylamine (2.15 mol) were added dropwise
with cooling to a suspension of 50.0 g of NbCl.sub.5 (185 mmol) in
300 ml of toluene. After stirring for 8 h at 23.degree. C. the
yellow solution was filtered and the solvent drawn off at 20 mbar.
The oily intermediate was dissolved in 250 ml of THF with no
further purification, and 31.2 g (185 mmol) of D.sup.tBuAD,
followed by 4.5 g of Mg powder (185 mmol), were then added. The
reaction mixture was stirred for 12 h at 23.degree. C., then the
solvent was drawn off at 20 mbar. The double extraction of the
residue with 250 ml of hexane each time produced a yellow, oily raw
product, which was purified by sublimation at 100.degree.
C./10.sup.-4 mbar. Yield: 30.8 g (41% of theoretical), melting
point 70.6.degree. C.
[0192] Elemental analysis: Calculated (%) for
C.sub.18H.sub.39N.sub.4Nb (M=404.44 g mol.sup.-1): C, 53.46; H,
9.72; N, 13.85. Found (%): C, 52.87; H, 9.59; N, 13.56.
[0193] MS-EI: 404 (M.sup.+, 22%), 389 (M.sup.+-Me, 10%), 332
(M.sup.+-CH.sub.3CNH, 4%), 57 (100%).
[0194] .sup.1H-NMR (C.sub.6D.sub.6, 300 MHz, 300 K): 5.86 (s, 2H,
CH-D.sup.tBuAD), 4.10 (s, 1H, NH), 1.54 (s, 9H, N.sup.tBu), 1.33
(s, 18H, .sup.tBu-D.sup.tBuAD), 1.26 (s, 9H, NH.sup.tBu).
[0195] .sup.13C{.sup.1H}-NMR (C.sub.6D.sub.6, 75 MHz, 300 K): 104.2
(CH-D.sup.tBuAD), 64.0 (NCMe.sub.3), 55.7 (CMe.sub.3-D.sup.tBuAD),
53.4 (NHCMe.sub.3), 35.1 (NCMe.sub.3), 34.1 (NHCMe.sub.3), 31.9
(CMe.sub.3-D.sup.tBuAD).
[0196] IR (KBr, cm.sup.-1): 3021(w), 1456(w), 1389(w), 1361(m),
1260(s), 1242(w), 1221(s), 1148(w), 1136(w), 1107(w), 1064(w),
1024(w), 980(w), 950(w), 870(w), 814(w), 771(w), 754(w), 592(w),
572(w), 515(w).
[0197] Although the invention has been described in detail in the
foregoing for the purpose of illustration, it is to be understood
that such detail is solely for that purpose and that variations can
be made therein by those skilled in the art without departing from
the spirit and scope of the invention except as it may be limited
by the claims.
* * * * *